Thanks for the constructive comment :D I'll take it in account, although I did try with cube buttons.

A tip: having trouble with cubes staying on buttons? Use the square cube button and/or put the button on a wall with a funnel on the opposite wall. This way the cube or ball will stay on the button. Same works if you have a funnel above a button on the floor.
Pretty simple but good execution. I never felt lost and the puzzles were intuitive enough I knew where I was going next.